1. Field of the Invention
The present invention relates to an image forming apparatus permitting recording of a color image and a monochromatic image and a method of forming an image. More particularly, the present invention relates to an image forming apparatus and a method of forming an image having a configuration permitting switching between a recording material for a color image and a recording material for a monochromatic image.
2. Description of the Related Art
There is conventionally known a copying machine or a facsimile machine permitting duplication of an original by adopting a scanner capable of reading out the original image in the read section. Among these apparatuses, ones adopting the ink jet system for the printer section has are known. The ink jet system is known as a system excellent in practicability for features including tranquility upon forming an image, a low running cost because of the possibility of printing on an ordinary sheet of paper, and suitability for recording a color image.
Among the image forming apparatuses of the foregoing type, there is available one capable of copying a color original by adopting a scanner which can read out both color and monochromatic originals in addition to recording of a color image. For the image forming apparatuses having such a configuration permitting recording of a color image, there is a demand for downsizing, cost reduction, quality improvement and achievement of operating convenience.
Among the image forming apparatuses adopting the foregoing ink jet system, a type is known in which a monochromatic cartridge and a color cartridge for a color image are from time to time interchangeable by a user, depending upon the use.
In an image forming apparatus adopting the ink jet recording system and permitting copying of a color original, when, for example, copying a monochromatic original, it is a conventional practice to record a monochromatic image by means of ink contained in the cartridge capable of recording a color image (for example, any of the colors in the ink cartridge, or process black expressing black by uniformly mixing all the colors). Also when recording a received facsimile image which is usually a monochrome, it is a common practice to record the facsimile-received monochromatic image by the use of ink in the ink cartridge if the apparatus mounts a cartridge for a color image.
When the ink cartridge capable of recording a color image is always used for recording, the ink may sometimes be exhausted, making it impossible to record a color image if the user tries to record a color image while mainly using the apparatus for recording monochromatic images. A method of avoiding this inconvenience is to largely increase the ink capacity of the ink cartridge. This technique results, however, in a larger scale of the apparatus and in a higher cost.
In a configuration in which a monochromatic cartridge and a color image cartridge are interchangeable, mismatching of the type of the attached cartridge with a desired image to be recorded makes it impossible to appropriately record the image after the apparatus once operates, leading to a wasteful consumption of paper and ink. A configuration requiring the user to identify the ink cartridge to be attached and to determine whether or not the ink cartridge is to be changed in response to the kind of image is defective in that operations to be conducted by the operator are complicated and may cause a malfunction.
When the paper size is different from the original size, a conventional apparatus discontinues reading out the image. When using the apparatus at home, for example, where it is difficult to always keep a stock of papers of various sizes, therefore, it is necessary to take the trouble of obtaining papers of an appropriate size for copying the original.
Another conceivable method is to record the image by reducing the size of the image in response to the paper size. However, particularly when copying a color original, a size reduction to match the paper size leads to a serious deterioration of the image quality. Therefore this technique is not a desirable solution. In order to form a high-quality color image, it is necessary to provide an expensive and complicated magnification changing circuit.
Further, when the paper size is smaller than the original size, and the original image is recorded at full size, the recording means, particularly if the ink jet method is adopted, ejects ink onto areas outside the paper. The interior of the apparatus is thus stained, and the ink even adheres to the next page of paper, thus staining the papers.
Asking the user at each time of use, whether recording is to be made at full size or at a reduced size when the paper size is different from the original size, or whether or not recording is to be made at full size and an area matching with the paper size is to be recorded when the paper size is smaller than the original size, requires complicated operations. When considering the personal or use at home use, in which it is difficult for the user to master the operations of the apparatus, it is not desirable to require complicated operations.